Means for automatically electrically controlling a fuel oil burning system



Jan, 10, 1939. D. H. McCORKLE 2,143,277

MEANS FOR AUTOMATICALLY ELECTRIGALLY CONTROLLING A FUEL QIL BURNING SYSTEM Filed 'June 1, 1956 3 Sheets-Sheet 2 4.3 5; I 42 /7 23 i 38 I .37 5 3 .32 I H6 I I I l y I I V 34 33 3 32'74o47464? ZNVENTZH.

Jan. 10, 1939. D. H. MGCORKLE 2,143,277

mums FOR AUTOMATICALLY ELECTRICALLY CONTROLLING A FUEL OIL BURNING 515mm Filed June 1, 1936 s Shets SheQt s v 77 77 1 l 6 I 75 v/ 1 w 74 44 a 4/ 7/ 74 v r 1r 3 7 5! 5 8 4- 1 /V mi 5/ 72 INYEYYTUE."

Patented Jan. 10, 1939 MEANS FOR AUTOMATICALLY ELECTRICAL- LY CONTROLLING A FUEL OIL BURNING SYSTEM Donald H. McCorkle, Berkeley, Calif., assignor to D. H. McCorkle 00., Berkeley, Calif., a corporation of California Application June 1, 1936, Serial No. 82,869

8 Claims.

This invention, a means for automatically electrically controlling a fuel oil burning system, relates to a new process and apparatus for controlling the fuel supply and its ignition and extinguishment in gravity type oil burners, and provides a positive, simple, non-magneticaily-actuated control system, which is controlled and operated throughout, through the agency of electrothermostatic means.

The usual type of electrical control for oil hurning systems utilizes electromagnets and mechanical devices for operation and control of the various elements, and certain of these elements require manual resetting under predetermined conditions, while this invention provides automatic resetting under all conditions.

It is a known fact that the fuel oil burner known to the art as the gravity type burner, is comparatively less expensive to produce and simpler to install than other types, in standard types of house-heating equipment. However, its application has been somewhat restricted due to the fact that an inexpensive, dependable fuel control system, which is entirely automatic, has not been made available.

To those familiar with the art, it is obviously known that in the gravity type of burner, the liquid fuel flows from storage by gravity to an oil level control, or container controlled by a constant level valve mechanism, which maintains a constant level or head of fuel in relation to the burner inlet. A metering valve is usually included in the oil level control or placed in circuit between this control and the burner for regulating the supply of fuel to the burner.

It is also common practice to .use a hot wire igniter in the burner for igniting the fuel, and whch usually consists of a suitable length of resistance wire energized by a suitable source of potential.

When electrical ignition means of this type is used, it is most advisable to maintain the ignition device at an ignition temperature over a sufficiently prolonged period previous to admission of fuel, and thereafter for a sufficient period to insure eflicient ignition and combustion within the chamber. and also to supply the fuel only after the ignition means is thoroughly heated to ignition temperature for the fuel, and then, to supply the fuel primarily at a rate which can be emciently handled by the igniting means and by the fuel already in process of combustion, so as to provide more eflicient and rapid ignition and obviate smoky combustion due to too rapid supply of fuel.

As the burner heats up and combustion is increased, the rate of vaporization increases, and the fuel supply to the burner should be correspondingly increased, gradually, to the full metered value.

Retention of the fuel until the igniter is heated to incandescence or full ignition temperature insures quick ignition of the fuel. If cold oil is admitted coincidently with energization of the igniter, the cold oil will conduct the heat from the igniter, and additional time will be required for the igniter to reach the ignition temperature.

Slow or sluggish ignition and combustion will result providing a prolonged period of smoky or sooty flame which fills the fire box with soot, wasting fuel and producing an undesirable heat insulating coating, which reduces the economy of operation, as also, undesirable smoky fumes from the chimney.

The objects and advantages of the invention are as follows; I

First; to provide elcctro-thermostatically actuated auxiliary metering means attachable to standard forms of fluid control devices, which will control the initial flow of fuel to the burner at a gradually increasing rate from zero to maximum metered flow as combustion in the burner increases.

Second; to provide means as outlined which will permit normal functioning of the standard metering means from the time said auxiliary metering means has attained its maximum flow position until such time ascurrent is interrupted thereto.

Third; to provide a system including a device as outlined, which upon electrical de-energization will seal fuel against admission to the standard i'iuid level control device, and again permit passage of fuel thereto after a predetermined period following re-energization.

Fourth; to provide a system as outlined with a series of actuating and control devices, each of which includes a pair of cooperative bimetal plates with interposed electrical heating element, which mechanically actuate devices employed in carrying out the method outlined.

Fifth; to provide an attachment for a standard oil level control, and a series of warp actuators and a warp element actuated switch in conjunction with a room thermostat, which will, upon the closing of the room thermostat circuit or completion of the circuit by other means, energize the igniter, and, after a predetermined period, gradually release a flow of oil to a burner, increasing from zero to full metered flow, and after a second predetermined period will break the igniter cirfailure of power or opening of the room'thermostat circuit.

tained sealed until the ignition device has attained an ignition temperature for the oil, after which the oil is gradually released from minute to full flow in direct ratio to the instant capacity of the burner to burn the oil in a substantially smokeless condition.

Gther objects andadvantages of the invention will become apparent as the following description is read on the drawings forming a part of this specification, and in which similar reference characters are used to designate similar parts throughout the several views, of which;

Fig. l is a wiring diagram of the invention.

Fig. 2 is an enlarged transverse section through the warp type thermostat used in all of the control devices.

trol attachment.

Fig. 4 is a sectional elevation of the auxiliary oil control attachment, taken on line 4-4 of Fig. 3, and shown attached to the usual type of oil level control.

Fig. 5 is a plan view of the igniter control.

Fig. 6 is a side elevation of Fig. 5 showing the igniter circuit closed.

Fig. 7 is a rear view of the igniter control.

Fig. 8 is a view similar to Fig. 6 except showing the igniter circuit open.

Fig. 9 is a sectional elevation through a modifled form of auxiliary oil control attachment applied to a type of oil control using a trigger and float arrangement of valve cut-01f, and shows the valve in released position.

Fig. 10 is a fragmentary view corresponding to Fig. 9, showing the auxiliary control in valve sealing position.

Fig. 11 is a side elevation of the igniter circuit switch control.

Fig. 12 is a front elevation of Fig. 11.

Fig. 13 is a sectional elevation through the igniter.

Fig. 14 is a plan view of the heating element for the warp thermostats.

The system includes the usualoil level control and metering valve, a delayed action auxiliary 011 control and oil seal, a room thermostat provided with a dial and a circuit breaking switch, an igniter control with delayed circuit breaking action and an igniter control switch, in conjunction with a supply of oil and an oil burning device.

Bi-metals, which are well known in the art, are used for all warp elements. Each warp element, respectively I1, I 8 and I9, consists of two cooperative bi-metal plates and 2| with interposed heating elements 22 consisting of the respective resistance elements 23, 24 and 25 insulated by means of sheet mica 26 or other suitable insulating material, each resistance element having suitable terminals. The warp elements are specifically described and claimed in co-pending ap- 39 moves freely in the amass? cuit, and which will seal oi the fuel supply upon plication, Serial No. 614,412; filed May 1, 1932, for Electric .valve. I v

The roomthermostat may be of any standard make and therefore requires no description, since the different types are well known in the art. The room thermostat is indicated at 21in the wiring diagram. I

The auxiliary oil control attachment in one form, consists of a base 28 having a slot 23formed therethrough, and a'hinge member 30 formed or secured at one end of the slot as shown. Hingedly connected at 3| to member 30,15 a counterweight lever 32 having a counterweight 33 secured to its free end.

Adjustably secured in the lever 32 is a'valve plunger 34, which cooperateswith the needle valve stem 35 of an oil level control 36, nuts 31 permitting most advantageous adjustment of this plunger relative to the stem 35. Y

Slidably and adjustably mounted through an aperture 38 formed through lever 32 is a timedelay lever-actuating connection 39 terminating at its lower end in a ball joint 40, the connection proper being threadedly adjustable in the connection head M and locked in adjusted position.

by means of the nut 42. The adjusted space between nut 42 and ball determines the time delay period.

Hingedly connected at one end to the connection head M as shown at 43 is a thermo-warp element i'i constructed as previously described} the other end of this element being secured to a pillar M as shown at 45, this pillar being adjustably secured in base 28 and locked in adjusted position by means of the nut 46.

A release cam. 41 is fixed on a shaft d3, which shaft is mounted in bearings 49 and 50, and a finger lever 5! is fixed on the projecting end of the shaft 48 to permit manual release of the valve 35 at will.

Suitable binding posts 52 and 53 are provided for the terminals of the resistance element of warp element i7, and suitable mounting holes 54 are provided for mounting the attachment on the oil level control 35. A ventilated cover 55 is provided for the unit.

The operation of this device is as follows; When the resistance element 23 is cut in circuit, the heat generated in the resistance element 23 causes the warp member l! to flex upwardly. This heating is accomplished very slowly through the use of a properly designed resistance element and proper application of potential. The warped position of this type of member is shown in Fig. 8.

During the initial warp period, the connection aperture without lifting lever 32, until the ball 40 cooperates with the undersurface of lever 32. This is the time delay period, since the counterweight 33 maintains the needle valve stem 35 depressed.

After the ball 40 .contacts lever 32, further flexing of element I! (which is very slowly accomplished), very slowly releases the needle valve by raising lever 32 to release stem 35, allowing the oil to enter the control unit 36 in a minute flow, gradually increasing to the metered adjustment of the unit 36. So long as the circuit remains unbroken through the'heating element 23, the member I! remains fully fiexed with the plunger 34 clearing the now free end of needle valve stem 35,

When a the circuit through 23 is broken the member l'l cools, permitting lever 32 to lower, plunger 34 contacting and depressing pin 35 and sealing the needle valve. Thus any interruption can be so used.

of current will cause the needle valve to be sealed.

A modification of the auxiliary control is shown in Figs. 9 and 10, applied to a float operated trigger-type valve seal. This type of control consists of the usual float 58 and a flood-- actuated float 51, to which is pivotally connected at one of its ends, the trigger lever 58 as shown at 58, this lever being pivotally mounted adjacent its other end as shown at 88, in a bearing 8| integral with the housing 62 or cover 88. A finger extension 88 is formed integrally with this lever and projects from the housing as shown. A trigger 65 is also formed integrally with this lever and terminates in a catch 88,

A plunger lever 81 has one end pivoted to the housing 62 or cover 88 as indicated at 88, the other end extending from the housing as a finger actuating lever 68, and integral with this portion of the lever is a retainer I8 which is cooperatively related to the trigger. A spring II cooperates with lever 81, forcing it down when released by the trigger 65.

' In operation, the needle valve I2 may be sealed by depressing finger lever 84 which releases the catch 88 from retainer I8, and spring 1| then snaps the lever 61, 6,8 to the position shown in Fig. 10, depressing needle valve stem I2.

If chamber 18 becomes flooded, the float 51' is raised and accomplishes the same result. To reset the valve, it is necessary to manually raise the finger lever 88 until retainer I8 is caught by catch 88.

To provide these adjustments automatically, an attachment is provided, consisting of a base I4 which is attachable to the oil control unit Just described.

A pillar 15 is adiustably mounted in the base and the warp element I1 is amzed at oneof its ends to the pillar as shown at I6, the other end cooperating with a slide or plunger 11 as shown at I8, the slot I8 forming another method of btaining time delay.

This slide is made sufficiently heavy to act by itself to keep the valve closed, and is mounted in. some suitable manner, such as in gibways 88 in the base I8, and has two inwardly projecting flngers 8| and 82 which respectively cooperate selectively with opposite sides of finger release levers 88 and 68.

Thus, when the member I1 is electrically heated, the member is flexed as shown in Fig. 9, this flexing being conducted slowly, the initial warp not in any degree releasing the valve I2,

' further warp raising lever 88 and releasing 88 until trigger 85 catches retainer 18, thus gradually opening the valve after a predetermined time delay, from zero to a completely free valve.

When current is interrupted to the resistance element 23, the warp element II cools and.returns to the position shown in Fig. it), gradually depressing lever 84 until member I8 is released,

, spring 'II then snapping lever88 to closing position as shown in Fig. 10. Thus any interruption of ourrent to heating element 28 will cause the valve I2 to be closed tightly. This device will work positively without the aid of a counterweight, and

Although the method of application has been described for only two units, any type of level control can be similarly controlled by this invention.

The time delay control for the igniter consists of a base 83, on which is mounted a pillar 84, to which is secured by one of its ends, the warp element I8,its other end being provided with an adjustable contact point 88, by means of which the time delay period is adjusted.

Also mounted on the base is a follower contact and conductor 88 which is formed of resilient material, and a stop 81 is flxed to the base and limits the opening movement of the member 88. Suitable binding posts 88, 88 and 88 are provided respectively for one side of the warp element resistance and warp member in parallel, for the other side of the resistance, and for the time delay element 88. k

In Figs. 6 and 7, the control is shown in its cold position, with the circuit completed through 88, I8, 85, 88 and 88.

Now, if the circuit is completed through 88 and 88, the resistance 24 will heat the" element I8 slowly, flexing member I8 slowly while the circuit through 85, 88 remains complete, until 88 is stopped by the travel limiting means 81, the member I8 continuing to warp, breaking circuit between 85 and 88.

When current is interrupted through 88, 88,

- the warp member I8 cools and returns to the position shown in Fig, 6, again closing the circuit through 88, I8, 88, 88 and 88.

The igniter control consists of a base 8!, on which is mounted a standard pin switch 82 having a plunger 88, which upon depression opens the switch, and on release closes the switch. This switch does not form a part of the invention, and any other similar type of switch can be substituted.

A warp element l8 has an adjustable screw 84 mounted at one of its ends for cooperation with the plunger 83, and has its other end afllxed to the pillar 85, which in turn is afllxed to the base 8|. Suitable binding posts 88 and 81 are provided for the resistance element 25, and other binding posts (not shown) are provided for the switch 82,

When member I8 is heated, it flexes upwardly, releasing pin 88 and switch 82 closes. When member I8 cools oil, it depresses pin 88, opening the switch.

The ignlter is of standard construction and consists of a section of metal conduit 88 carrying insulated conductors 88 and I88 to the resistance or heater wire I8I, which is heated by a suitable supply of current, and is installed in the furnace I82 in cooperative relation to admitted oil I88 which it ignites.

The wiring diagram Fig. 1 illustrates the system in its entirety and includes the apparatus described.

A suitable source of potential is supplied through main line conductors I86 and I85, which are connected directly to the primary I88 of a step-down transformer I81. The room hermostat 21 is connectedto one side of the secondary I88 of this transformer through a conductor I88, this thermostat normally maintaininga broken circuit above a predetermined temperature in the room. When the temperature drops, the thermostat closes a switch, completing a circuit through contact H8, through wire I I I, resistance element 2-8 of warp member I8. wire H2 to the other side of the secondary I88 of transformer I81, coincidently making circuit through member I8, contact 85, follow member 86, wire H3, resistance 25 of warp member i8, through wire H4 to conductor H2 to secondary I88. and, coincidently making circuit from contact I I8 through wire H to resistance element 28 of warp member I'I thence through wire 5 to secondary I88.

amaaw Thus all warp members are simultaneously heat is maintained released until the condition of ed, but at diii'erent rates.

The initial heating of warp member I9 releases pin 93, permitting switch 92 to close to contact 1, closing a circuit from line I04 through wire II8, switch 92, contact I", wire 9 to primary I20 of step-down transformer I2I, thence through wire I22 to line I05.

The closing of this last circuit energizes the secondary I23 of transformer I2I, the terminals of this secondary being connected to the respective terminals 99 and I00 of the igniter resistor l0l, heating this resistor.

During this period, all warp elements are heating and flexing slowly. The initial warp ofelement 99 has permitted switch-92 to close. The initial warp of member I! has not in the least opened valve 35, but further warp very slowly releases the valve, permitting a minute flow of oil I03 to burner I02, which is gradually increased. By this time, the igniter is heated to ignition temperature for the oil, and this small quantity of oil is ignited, and as the furnace or stove heats up, an increasing flow of oil is supplied by further warp of member I! and can be handled efficiently by the burner, until finally the valve stem is completely freed and the maximum metered flow of oil is delivered to the burner.

By this time, the oil is burning efficiently and the igniter is no-longer required. Also, the warp element I8 has flexed sufiiciently to clear the contact 86 after the opening of this member has been stopped by stop 81. The circuit is therefore broken through resistance 25 at contact 85, and element l9 cools, and after the element is sufliciently cooled, it depresses-plunger 93, opening switch 92, Ill, breaking the circuit to primary I20 of transformer I2I, while elements It and I1, being constantly heated, remain in their maximum flexed position.

Should the temperature in the room rise above a predetermined value, or in the event of power failure, the circuit will be interrupted, allowing both elements I8 and I! to cool, closing circuit 85 and I36 and closing valve 35 or I2. Thus all contingencies are guarded against,

It will be understood that variations in .the method, system, or construction and arrangement of parts, which variations are consistent with the appended claims, may be resorted to without detracting from the spirit or scope of the invention or sacrificing any of the advantages thereof.

I claim:

1. In a fuel-burning system having a heat-.

regulating thermostat and an electric igniter for igniting fuel; a mechanical switch controlling said igniter; a first warp element controlled by said thermostat; a second warp element controlled by said first warp element and controlling said mechanical switch, said second warp element being constructed for closing said switch upon initial actuation and opening said switch after a predetermined time delay period independently of the control of said first warp element by said thermostat.

2. A system as claimed in claim 1; a fuel-flow control valve; a third warp element controlled by said thermostat and controlling said valve, releasing said. valve to open after a predetermined time delay period, whereby said igniter and said valve are actuated in sequential timedelay relation, and said igniter is actuated througha predetermined period of time independently of said thermostat, while said valve the thermostat ature.

3. In a fuel burning system, fuel ignition means and a circuit therefor; a mechanical switch conis changed by change in tempertrolling said circuit; a first warp element nor-' mally maintaining said switch in circuit-breaking position, a first heating resistance for said first warp element and a first circuit therefor; a second warp element normally maintaining said first circuit closed through said first heating resistance, and a second heating resistance for said second warp elementand a second circuit therefor; a heat-regulating thermostat controlling said first and second circuits for initial operation; means breaking circuit through said second warp element and said first heating resistanceafter a termined period of time independently ofthe circult control of said heat-regulating thermostat.

4. In a fuel burning system, fuel ignition means and a circuit therefor; a gravitationally closed switch controlling said circuit; a first warp element normallymaintaining said switch in open position; a first heating resistance for said first warp element and a first circuit therefor; a second warp element normally maintaining said first circuit closed through said first heating resistance, and a second heating resistancefor said second warp element and a second circuit for said second heating resistance; a heat regulating thermostatic switch controlling said first circuit for closing and opening and said second circuit for closing only; a resilient conductive follower in circuit with said first heating resistance and normally in circuit-making contact/with said second warp element; and means limiting the travel of said follower, whereby, after a predetermined degree of warping of said second warp element said first circuit will be broken and said first warp element will release said gravitationally-closed switch to open alter a predetermined time delay period irrespective of the control of said circuits by said heat-regulating thermostatic switch.

5. A system as claimed in claim 4, and including a fuel-flow control valve, a third warp element having a third heating resistance controlled by said thermostatic switch, said third warp element controlling said valve, releasing said valve to open after a predetermined degree of warping of said third warp element, whereby said ignition means and said valve are actuated in sequential time delay relation, with the valve released during the entire closed period of said thermostatic switch.

6. In a fuel burning system, a mechanical switch for controlling an ignition circuit; a first warp element normally maintaining said switch open and a first heating resistance for said first warp element; a resilient follower connected in series with said first heating resistance and stop means limiting the movement of said follower in one direction; a second warp element normally completing a first circuit through said iollower and maintaining said follower in depressed position relative to said stop means, and a second heating resistance for said second warp element and a second circuit for said second heating resistance; and a heat-regulating thermostatic I switch controlling said second circuit, and conpredetermined degree of warping of said second multaneously completed, said mechanical switch will be closed upon initial flexing of said first warp element, said first circuit will be broken upon. cooperation of said follower with said stop means and said mechanical switch opened by said first warp element after a predetermined period of time irrespective of the control of circuits by said thermostatic switch.

7. A system as claimed in claim 6 and including; a fuel-flow control valve; means normally maintaining said valve closed, a third warp element and a heating resistance therefor controlled by said thermostatic switch; and an operative connection between said means and said third warp element effecting release of said valve to open only after a predetermined degree of flexing of said third warp element, whereby, with simultaneous closing of all circuits by said thermostatic switch, said mechanical switch will be closed a predetermined period of time in advance oi the release of said valve.

d. An oil-binning system comprising; a first circuit including a first transformer secondary and an ignition resistance; a second circuit including a source of potential, it normally-open mechanical switch and the primary of said first transformer; a third circuit including the secondary of a second transformer, a first heating resistance, a follower, a first warp element, and a room thermostahc switch; a fourth circuit ineluding said secondary of said second transformer, said thermostaticswitch, and a second heatin resistance for said first warp element; a fifth circuit including said secondary of said second transformer, said thermostatic switch, and athird heating resistance; the primary of said second transformer being connected across said source of potential; a second warp element for said first heating resistance'flexing upon heating to release said mechanical switch forciosing said second circuit to heat said ignition resistance and upon cooling to open said rriechanical switch to terminate heating of said ignition resistance; a stop element for said follower causing said first warp element to break circuit therewith after a predetermined degree of flexing of said first warpelement; and a third warp element for said third heating resistance; means normally maintaining said fuel-supply valve closed and having an operative connection with said third warp element releasing said valve to open only after a predetermined degree of flexing of said third warp element, whereby, upon closinc of said thermostat switch, all warp elements are coincidently heated, the ignition resistance is heated for a. predetermined period of time before release of said valve, and for a total predetermined period of time independently oi the closed or open position of said thermostatic switch. 

